Nickel stabilisers for synthetic polymers

ABSTRACT

New complexes of nickel salts of hydroxybenzoic acids are stabilizers for polymers. The complexes are prepared by reacting a nickel benzoate with a corresponding alkohol.

United States Patent [1 1 Rasberger et a1.

[4 1 Aug. 26, 1975 NICKEL STABILISERS FOR SYNTHETIC POLYMERS [75] Inventors: Michael Rasberger, Allschwil;

Johann Rody, Basel; Paul Moser,

Riehen; Helmut Muller, Binningen, all of Switzerland [73] Assignee: Ciba-Geigy Corporation, A'rdsley,

[22] Filed: June 14, 1973 [21] Appl. No.: 370,180

[30] Foreign Application Priority Data June 21, 1972 Switzerland 9333/72 52 us. on 260/439 R; 260/4575 N; 260/242;

260/270 R; 260/3268 [51] Int. Cl. C07j 15/04 58 Field of Search 260/439 R, 45.75 N

FOREIGN PATENTS OR APPLICATIONS 991,591 5/1965 United Kingdom 945,050 12/1963 United Kingdom Primary ExaminerArthur P. Demers Attorney, Agent, or F irmNestor W. Shust; Charles W. Vanecek [57] ABSTRACT New complexes of nickel salts of hydroxybenzoic acids are stabilizers for polymers. The complexes are prepared by reacting a nickel benzoate with a corresponding alkohol.

3 Claims, No Drawings NICKEL STABILISERS FOR SYNTHETIC POLYMERS Ni L n H O m wherein R represents hydrogen or alkyl with 1 to carbon atoms, and one of the substituents R and R represents an alkyl radical with 3 to 8 carbon atoms and the other represents COO m is a number from 1 to 2, n is a number from 0 to 2, and L is a ligand a. of the formula 4 6 7 8 R R R R \N ca c'H (di or R5 P 1 R represents hydrogen, alkyl with l to 4 carbon atoms or the radical of the formula R6 R7 R8 i l l-l CH (ClUp Orl or R and R together with the nitrogen atom represent the radical of a 5- or 6-membered heterocycle of the pyrrolidine, piperidine, piperazine, or morpholine series, R, R and R represents hydrogen or one of R, R and R represents alkyl with l to 4 carbon atoms, and p is O or 1, or

b. of the fonnula 9 R /Cll Oll R10 ca OH wherein R represents hydrogen, alkyl with l to 4 carbon atoms, OH, NH;, CH OCH C(CH OH) or -CH OH, and R represents hydrogen, CH OH or alkyl with l to 4 carbon atoms, or

c. of the formula CH 2 OH wherein R represents hydrogen, alkyl with l to 4 car bon atoms or CH OR and R represents hydrogen, alkyl with l to 18 carbon atoms, or phenyl, or

d. of the formula wherein R represents OH,

or OCH CHOHCH OH,

R represents hydrogen or alkyl with 1 to 4 carbon atoms, R represents hydrogen or alkyl with l to 4 carbon atoms, and q is 2 or 3, or

e. a mixture of the ligands cited under (a), (b), (c),

and (d).

Preferred compounds are those of the formula I, wherein R represents hydrogen or alkyl with l to 4 carbon atoms, and one of the substituents R and R represents an alkyl radical with 3 or 4 carbon atoms and the other represents COO m is a number from 1 to 2, in particular 1 to 1,5, n is a number from O to 2, in particular 0.3 to 0.8, and L represents a ligand a. of the formula l l i \s on cu (cu) on wherein R represents hydrogen, alkyl with l to 4 carbon atoms, cyclohexyl, phenyl, or a radical of the formula R R R l l l -Cll CH (Cll)p OH R R R l l I -CH CH (ClDp OH R and R together with the nitrogen atom represent the radical of a 5- or 6-membered, saturated heterocycle of the pyrrolidine, piperidine, piperazine, or morpholine series, R, R, and R represent hydrogen or one of R, R", and R represents methyl, and p is or l, or

b. of the formula R /CH 0H l0 R CH OH wherein R represents hydrogen, methyl, OH, Nl-l or -CH OH, and R represents hydrogen, CH OH or methyl, or

c. of the formula 11 R -CHOH (Ii-1 0B wherein R represents hydrogen, alkyl with l to 4 carbon atoms, or CH OR and R represents hydrogen, alkyl with l to 12, especially 8 to 12, carbon atoms, or represents phenyl, or

d. of the formula t .5 R (CH-CH -0-) R wherein R represents OH,

or OCH CHOHCH OH, R represents hydrogen or methyl, R represents hydrogen or ethyl, and q is 2 or 3.

Particularly preferred compounds are those of the formula la tert .Butyl G) i- P COO N1 m n tert .Butyl 2 wherein m is a number from 1 to 2 and n is a number from 0 to 2, and L is defined in the same manner as in the preferred compounds under (a) with p being 0, and in those under (b), (c), and (d).

The surprising discovery has been made that the compounds of the formula I, either as single compounds or as mixtures, are good stabilisers for polymers cessed at greatly elevated temperature without the polyolefines becoming discoloured as they are by the previously known nickel benzoates. It is known further to stabilise polyolefines by thiobisphenol-nickelalkanolamine complexes. Compared with these compounds, the new nickel complexes display evidence of a much better light stability.

According to definition, R to R", R and R can be alkyl groups. Within the limits indicated under the formula I these groups can be methyl, ethyl, n-propyl, isopropyl, n-butyl, sec. butyl, tert. butyl, n-amyl, tert. amyl, n-hexyl, n-octyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl, or n-octadecyl.

Together with the nitrogen atom R and R can represent the radical of a heterocycle of the pyrrolidine series, e.g. pyrrolidine, 3-pyrrolidinol, of the piperidine series, e.g. piperidine, 2,6-dimethyl-piperidine, 4- hydroxy-piperidine, 4-methylpiperidine, of the piperazine series e.g. N-methylpiperazine, piperazine, N-2-hydroxyethylpiperazine, or of the morpholine series, e.g. morpholine, 2,5- and 3,5-dimethylmorpholine.

The compounds of the formula I protect polymers against degradation, preferably a-olefine polymers, e.g. polypropylene, optionally cross-linked polyethylene, polyisobutylene, polymethylbutene-l, polymethylpentene-l polybutene-l polyisoprene, polybutadiene; also polystyrene and copolymers thereof e.g. polyacrylonitrile-styrene copolymers or polyacrylonitrilebutadiene-styrene copolymers; copolymers of the monomers based on the cited homopolymers, e.g. ethylene-propylene copolymers, propylene-butene-l copolymers, and terpolymers of ethylene and propylene with a diene, e.g. hexadiene, dicyclopentadiene or ethylidene-norbornene; mixtures of the above cited homopolymers, for example mixtures of polypropylene and polyethylene, polypropylene and polybutene-l polypropylene and polyisobutylene. Preferred are polypropylene and its mixtures and the copolymers which contain the propylene units.

The compounds of the formula 1 are incorporated into the substrates in a concentration of 0.01 to 5% by weight, based on the material to be stabilised. Preferably 0.05 to 1.5, but more preferably still 0.1 to 0.8% by weight of the compounds, based on the material to be stabilised, is incorporated into it,

The incorporation can be effected after the polymerisation by blending at least one of the compounds of the formula I and optionally further additives into the melt by methods conventionally used in the art, either before or during the moulding, or also by applying the dissolved or dispersed compounds to the polymer, optionally with subsequent evaporation of the solvent.

The compounds of the formula I can also be incorporated into the polymer to be stabilised in the form of a master batch which contains the nickel stabiliser e.g. in a concentration of 2.5 to 25% by weight.

In the case of cross-linked polyethylene, the compounds are added before the cross-linking.

As further additives together with which it is possible to use the stabilisers, the following may be cited:

1. Antioxidants of the aminoand hydroxyaryl series. In the case of the latter, the sterically hindered phenol compounds may be cited, e.g.; 2,2'-thiobis-(4-methyl-6-tert.butylphenol), 4,4-thiobis-(3-methyl-6-tert.butylphenol), 2,2'-methylene-bis-(4-methyl-6-tert.butylphenol), 2,2'-methylene-bis-(4-ethyl-6-tert.butylphenol, 4,4'-methylene-bis-(2-methyl-6-tert.butylphenol), 4,4'-butylidene-bis-(3-methyl-6-tert.butylphenol), 2,2'-methylene-bis-[4-methyl-6-(a-methylcyclohexyD- phenol], 2,6-di-(2-hydroxy-3-tert.butyl-5-methylbenzyl)-4- methyl-phenol,

2,6-di-tert.butyl-4-methylphenol,

1,1,3 ,-tris-2-methyl-( 4-hydroxy-5-tert.butyl-phenyl)- butane,

l ,3 ,5-trimethyl-2,4,6-tri-( 3 ,5-di-tert.butyl-4-hydroxybenzyl)benzene,

esters of B-4-hydroxy-3,5-di-tert.butylphenyl-propionic acid with monoor polyvalent alcohols, such as methanol, ethanol, octadecanol, hexane diol, nonane diol, trimethylhexane diol, thiodiethylene glycol, trimethylol ethanes or pentaerythritol. 2,4-bis-octylmercapto-6-(4-hydroxy-3,S-di-tert- .butylanilino)-s-triazine, 2,4-bis-(4-hydroxy-3,5-di-tert.butylphenoxy)-6- octylmercapto-s-triazine,

l, 1 ,-bis-( 4-hydroxy-2-methyl-5-tert.butyl-phenyl )-3- dodecylmercapto-butane, 4-hydroxy-3,5-di-tert.butylbenzyl-phosphonic such as dimethyl-, diethylor dioctadecyl ester, (3-methyl4-hydroxy-5-tert.butylbenzyl)malonic aciddi-octadecyl ester,

S-( 3 ,5 -dimethyl-4-hydroxyphenyl )-thioglycolic octadecyl ester,

esters of bis-(3,5-di-tert.butyl-4-hydroxybenzyl)- malonic acid, such as didodecyl ester, dioctadecyl ester, 2-dodecylmercaptoethyl e.g.:

Among the aminoaryl derivatives, mention may be made of aniline and naphthylamine derivatives and their heterocyclic derivatives, e.g.

Phenyll -naphthylamine, phenyl-2-naphthylamine, N,N-diphenyl-p-phenylenediamine, N,N-di-2-naphthyl-p-phenylenediamine, N,N-di-sec.butyl-p-phenylenediamine, 6-ethoxy-2,2,4-trimethyl-l ,2-dihydroquinoline, 6-dodecyl-2,2,4-trimethyl-1,2-dihydroquinoline, monoand dioctyliminodibenzyl,

polymerised 2,2,4-trimethyl-1,2-dihydroquinoline.

When using the compounds of the formula I in combination with the above cited amino compounds, it must be pointed out that, on account of the tendency of these latter to cause discolouration, the stabilised polymer no longer possesses such good colour properties.

2. Ultraviolet absorbers and light filters, e.g.:

a. 2-(2-hydroxyphenyl)-benztriazoles, for example the 5-methyl-; 3',5'-di-tert.butyl; 5'-tert.butyl-; 5- chloro-3,5 di-tert.butyl-; 5-chloro-3'-tert.butyl-5- methyl-; 3 ',5 '-di-tert.-amyl-; 3 -methyl-5 -B-carbomethoxyethyl-; 5-chloro-3 ',5 -di-tert.amyl-derivative,

b. 2,4-bis-(2-hydroxyphenyl-6-alkyl-s-triazines, e.g. the 6-ethyl or 6-undecyl derivative,

0. 2-hydroxy-benzophenones, e.g. the 4-hydroxy, 4- methoxy, 4-octoxy, 4-decyloxy, 4-dodecyloxy, 4,2',4'- tri-hydroxy or 2'-hydroxy 4,4'-dimethoxy derivative,

ester,

acid

d. l,3-bis-(2-hydroxy-benzoyl)-benzenes, e.g. l,3- bis-(2-hydroxy-4-hexyloxy-benzoyl)-benzene, l,3- bis-(2'-hydroxy-4'-octoxy-benzoyl)-benzene, 1,3-bis- (2-hydroxy-4'-dodecyloxy-benzoyl )-benzene.

e. Aryl esters of optionally substituted benzoic acids, e.g.: phenylsalicylate, octylphenylsalicylate, dibenzoylresorcinol, benzoyl-resorcinol, 3,5.di-tert.butyl-4-hydrobenzoic acid-2,4-di-tert.butyl-phenyl or -ocatdecyl ester.

f. Acrylates, e.g.: a-cyano-Bfi-diphenylacry]ic acid ethyland isooctyl ester, a-carbomethoxy-cinnamic acidmethyl ester, a-cyano-B-methyl-p-methoxycinnamic acidmethyl and butyl ester, N-(B- carbomethoxy-vinyl)-2-methyl-indoline.

g. oxalic acid diamides, e.g. 4,4'-dioctyloxyocanilide, 2,2-di-octyloxy-5,5'-di-tert.butyloxanilide, 2,2 '-di-dodecyloxy-5 ,5 -di-tert.butyloxanilide,

3. Nucleination agents, e.g. 4-tert-butylbenzoic acid, adipic acid, diphenylacetic acid. 4. Compounds which decompose peroxide, e.g. esters of B-thiodipropionic acid, for example lauryl, stearyl, myrystyl or tridecyl ester, salts of 2- mercaptobenzimidazols, for example the zinc salt, and diphenylthiourea. 5. Other additives, such as plasticisers, antistatic agents, dyeing assistants, flame-proofing agents, pigments, carbon black, asbestos, glass fibres, china clay, talcum, and flowing agents. 6. Costabilisers, e.g. salts of earth alkalies, preferably salts of earth alkalies and carboxylic acids, e.g. calcium stearate, calcium palmitate, calcium oleate, and calcium laurate.

The compounds according to the invention of the formula I R1 .1 HOQ-Rf Ni L R2 2 can be manufactured by various methods. For example, it is possible to dissolve 1 mole of the compound II 3 H0 R Ni n.H O n wherein R, R and R have the meanings given under the formula I, in an organic solvent, and with the application of heat to react the solution with ligands L, whose nature and composition are derived from the meaning given under the formula I, to give the compound I.

Suitable solvents for this reaction are chiefly alcohols, in particular methanol, ethanol, and isopropanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, dioxan, tetrahydrofuran, acetonitrile, and mixtures of these solvents.

7 A further possibility of obtaining compound I consists in refluxing compound II with ligands L in an organic solvent for a lengthy period of time over a steam trap.

For this process there are used accordingly solvents 5 with the aid of which it is possible to distill off water azeotropically, for example benzene, toluene, xylene etc.

An end product with a specific amount of water bonded as a complex, i.e. with a specific value for n in formula I, is obtained by the first process by using a compound of the formula II with corresponding water content.

In both these above cited processes it is also possible tert.butyl The following Examples describe the invention in more detail, the parts and percentages being by weight.

EXAMPLE 1 A solution of 28.7 parts of Ni-3,5-di-tert.butyl-4- hydroxybenzoate, which contains 2.36% of water bonded as a complex, in 250 ml of absolute ethanol is treated dropwise with 7.5 parts of triethanolamine in 10 100 m1 of absolute ethanol. The mixture is stirred for 15 hours at room temperature and subsequently refluxed for 2 hours. The solvent is distilled off in vacuo and the green residue is then dried for 20 hours at 60C and 15 mbar. The complex consisting of 1 mole of Ni- 15 benzoate, 1 mole of triethanolamine, and water has the following composition:

Cale. Ni 8.0%

(on 1.19% water content) found Ni 8.16%

found H O 1.19%

The following compounds were manufactured in analogous manner:

H Ni.L n 11 0 "tart butyl 2 Nr. Ligand L Cale Found I Ni. in 7. 141 in v. 0 in 2 NH(CH CH Ol-l) 8,96 8,36 0, 1,0

{I (CH3)2NCH2CH2CH2OH 8,80 8,66

5 CH3NHCH2CH-2OH 9,16 8,97 1,3 4

6 (CH3)2NCH2CH2OH 8,98 8,72 1,10

7 0 14 11 (LH2LHZ0H)2 8,13 2 0 t J 9 (011 28011 0809.015 8,74 1 10 N(0H cricviecu 7,77 7,38 1,01 11. 1'hll(Crl CI-l O1-1) 7,86 7,54 12 cncn cn oa 8,47 8,37 13 ul'- )-:c;: cn 0;--: 8,46 8,0) 1 ,6. 1 1-" 11 Nt:(c:1-1 0t-;) 8,5 1 8,31 1,4?

P11 15 Ncn.,c:n.,02i 1,

on on? L 16 11001-1 021 @{Jccnfllfitt 7,97. 7,58 3.7 1 11011 011 0628 821 011 8,71 8,57 18 Ph -2111611 021 03 8,36 8,09 19 110811 6310210 3,80 9,01 1,01 \fl} H, r )[,0 0 513 20 a a (M c 7 6.) 7 2.1 0 11. .0112! 7, 12 6 86 O. I

:0. ',38 11,-": az g thi ((1.... c. 6. 011 7 M" Ph represents phenyl EXAMPLE 2 EXAMPLE 3 1000 parts of polypropylene powder [melt index 1.5 g/10 minutes (230C 2160g)] are mixed in a drum mixer with 0.5 part of tetrakis-B(3,5-di-tert.butyl-4- hydroxyphenyl)propionic acid pentaerythritol ester, 3 parts of dilaurylthio-dipriopionate (DLTDP) and 5 parts of a UV rays absorbing agent of the following Table and subsequently homogenised at 200C for minutes in a Brabender plastograph. The polymer substance is then pressed for 6 minutes at 240C in a heated press to 1 mm thick sheets.

A visual evaluation of the test specimens for their discolouration gives the following results:

EXAMPLE 4 1000 parts of polypropylene powder [melt index 1.5 g/lO minutes (230C, 2160 g)] are mixed in a drum mixer with 1 part of of [3-(3,5-di-tert.-butyl-4-hydroxyphenyl)propionic acid octadecyl ester and 5 parts of a UV rays absorbing agent of the following Table and subsequently granulated at a temperature of 200C in a Ko-kneader. The resulting granules are processed in the customary manner over an extruder with slot die to a sheet which is cut into ribbons which are subsequently stretched at elevated temperature in the stretch ratio 1:6 and wound up (titre of the ribbons: 700-900 den; ultimate tensile strength: 5.5-6.5 g/den).

The polypropylene ribbons are applied without tension to test carriers and exposed in a xenotest device 150. Five test specimens are taken after different times and their ultimate tensile strength is determined. The exposure time after which the ultimate tensile strength of the ribbons has declined to of the starting value is taken as the criterion for the protective action of the individual UV rays absorbing agents. The values obtained are listed in the following Table:

Appearance of the sheet 1 P v, i\o. UV rays ab..o1b1.ng agent after 6 mins at 240C ticrrl: butyl (Without i? grey discolouration P C- Ni tort; butyl 2 water content).

1. no discolouration 2 no discolouration 3 faint grey tinge no discolouration 7 no discolorouration 1O faint grey tinge 11 no discolouration 19 no discolouration 21 no discolouration 7 Hours of exposure to No. UV lays HbSOITbIHg a ,ent: 5oz. ultimate tensile strength (without tert.butyl ligimd wit. 1 H 1' 0 OD l\l 2 36 Z tert .buty] water content) We claim: wherein n is 0.42. I 1. Compound of the formula 40 3. Compound of the formula tert.butyl G) Ho COO N1 (1&9 N(CH CH OH) n .11 0

teit .butyl 2 tert. buty]. G)

H0 f.) coo T- 696 c H N on on o m 4 9 2 2 H) n.l-l 0 tert .but'yl 2 wherein n is 0.47. 60 wherein n is 0.51.

2. Compound of the formula tart. butyl (D OO. unwn cv om n n 0 tert butyl 2 

1. COMPOUND OF THE FORMULA
 2. Compound of the formula
 3. Compound of the formula 